The use of genotypes with high biomass and nutrient accumulation but low nutrient harvest indices (ratio between nutrient amount in grains and in shoots) could reduce nutrient removal by harvesting and improve agricultural sustainability. The low variability found in the harvest indices in common bean (Phaseolus vulgaris L.) calls for the evaluation of a wide range of genotypes. This study evaluated the variability of nutrient harvest indices and their relationship with grain yield in common bean genotypes. A field experiment was carried out in Seropédica, State of Rio de Janeiro, with 64 bean genotypes (41 cultivars, 12 breeding lines and 10 landraces from the South of Brazil) in four replications. The harvest indices were based on the amounts of biomass and nutrients accumulated in grains, stems and pod hulls after pod threshing. The average grain yield was 205 g m-2, with average harvest indices of biomass, N, P, K, Ca, and Mg of 0.62, 0.83, 0.89, 0.58, 0.33, and 0.51 g g-1, respectively, indicating an intense translocation of N and P to grains. The variability of these indices was relatively narrow. The residue dry mass after pod threshing was on average 107 g m-2, and contained 2.0, 0.15, 3.6, 2.8 and 1.3 g m-2 of N, P, K, Ca and Mg, respectively, wich suggests that these residues can meet a relatively great part of the crop nutrient demand. The phenotypic and genetic correlations (p < 0.001) were high, positive between grain yield and harvest indices of biomass and N, and negative between grain yield and N and P grain concentrations. Since the phenotypic and genetic correlations between grain yield and P harvest index were less significant (p < 0.01), some genotypes with low P harvest index but good yields could be identified. The selection of common bean genotypes for improved grain yield can result in higher harvest indices of biomass and N, and also in larger nutrient amounts in grains and lower N and P grain concentrations.
nitrogen; phosphorus; common bean; Phaseolus vulgaris; diversity